Add encoder abstraction. (#21548)

24 files changed, 509 insertions, 414 deletions

diff --git a/quantum/encoder.c b/quantum/encoder.c
index efb780c474..735eb1cd71 100644
--- a/quantum/encoder.c
+++ b/quantum/encoder.c
@@ -1,81 +1,110 @@
-/*
- * Copyright 2018 Jack Humbert <jack.humb@gmail.com>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
+// Copyright 2022-2023 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
 
-#include "encoder.h"
-#include "keyboard.h"
+#include <string.h>
 #include "action.h"
-#include "keycodes.h"
+#include "encoder.h"
 #include "wait.h"
 
-#ifdef SPLIT_KEYBOARD
-#    include "split_util.h"
-#endif
-
-// for memcpy
-#include <string.h>
-
 #ifndef ENCODER_MAP_KEY_DELAY
-#    include "action.h"
 #    define ENCODER_MAP_KEY_DELAY TAP_CODE_DELAY
 #endif
 
-#if !defined(ENCODER_RESOLUTIONS) && !defined(ENCODER_RESOLUTION)
-#    define ENCODER_RESOLUTION 4
-#endif
+__attribute__((weak)) bool should_process_encoder(void) {
+    return is_keyboard_master();
+}
 
-#if !defined(ENCODERS_PAD_A) || !defined(ENCODERS_PAD_B)
-#    error "No encoder pads defined by ENCODERS_PAD_A and ENCODERS_PAD_B"
-#endif
+static encoder_events_t encoder_events;
+
+void encoder_init(void) {
+    memset(&encoder_events, 0, sizeof(encoder_events));
+    encoder_driver_init();
+}
 
-extern volatile bool isLeftHand;
+static bool encoder_handle_queue(void) {
+    bool changed = false;
+    while (encoder_events.tail != encoder_events.head) {
+        encoder_event_t event = encoder_events.queue[encoder_events.tail];
+        encoder_events.tail   = (encoder_events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
 
-static pin_t encoders_pad_a[NUM_ENCODERS_MAX_PER_SIDE] = ENCODERS_PAD_A;
-static pin_t encoders_pad_b[NUM_ENCODERS_MAX_PER_SIDE] = ENCODERS_PAD_B;
+#ifdef ENCODER_MAP_ENABLE
 
-#ifdef ENCODER_RESOLUTIONS
-static uint8_t encoder_resolutions[NUM_ENCODERS] = ENCODER_RESOLUTIONS;
-#endif
+        // The delays below cater for Windows and its wonderful requirements.
+        action_exec(event.clockwise ? MAKE_ENCODER_CW_EVENT(event.index, true) : MAKE_ENCODER_CCW_EVENT(event.index, true));
+#    if ENCODER_MAP_KEY_DELAY > 0
+        wait_ms(ENCODER_MAP_KEY_DELAY);
+#    endif // ENCODER_MAP_KEY_DELAY > 0
 
-#ifndef ENCODER_DIRECTION_FLIP
-#    define ENCODER_CLOCKWISE true
-#    define ENCODER_COUNTER_CLOCKWISE false
-#else
-#    define ENCODER_CLOCKWISE false
-#    define ENCODER_COUNTER_CLOCKWISE true
-#endif
-static int8_t encoder_LUT[] = {0, -1, 1, 0, 1, 0, 0, -1, -1, 0, 0, 1, 0, 1, -1, 0};
+        action_exec(event.clockwise ? MAKE_ENCODER_CW_EVENT(event.index, false) : MAKE_ENCODER_CCW_EVENT(event.index, false));
+#    if ENCODER_MAP_KEY_DELAY > 0
+        wait_ms(ENCODER_MAP_KEY_DELAY);
+#    endif // ENCODER_MAP_KEY_DELAY > 0
+
+#else // ENCODER_MAP_ENABLE
+
+        encoder_update_kb(event.index, event.clockwise ? true : false);
+
+#endif // ENCODER_MAP_ENABLE
+
+        changed = true;
+    }
+    return changed;
+}
 
-static uint8_t encoder_state[NUM_ENCODERS]  = {0};
-static int8_t  encoder_pulses[NUM_ENCODERS] = {0};
+bool encoder_task(void) {
+    bool changed = false;
 
-// encoder counts
-static uint8_t thisCount;
 #ifdef SPLIT_KEYBOARD
-// encoder offsets for each hand
-static uint8_t thisHand, thatHand;
-// encoder counts for each hand
-static uint8_t thatCount;
-#endif
+    // Attempt to process existing encoder events in case split handling has already enqueued events
+    if (should_process_encoder()) {
+        changed |= encoder_handle_queue();
+    }
+#endif // SPLIT_KEYBOARD
+
+    // Let the encoder driver produce events
+    encoder_driver_task();
+
+    // Process any events that were enqueued
+    if (should_process_encoder()) {
+        changed |= encoder_handle_queue();
+    }
+
+    return changed;
+}
+
+bool encoder_queue_event(uint8_t index, bool clockwise) {
+    // Drop out if we're full
+    if ((encoder_events.head + 1) % MAX_QUEUED_ENCODER_EVENTS == encoder_events.tail) {
+        return false;
+    }
+
+    // Append the event
+    encoder_event_t new_event                 = {.index = index, .clockwise = clockwise ? 1 : 0};
+    encoder_events.queue[encoder_events.head] = new_event;
+
+    // Increment the head index
+    encoder_events.head = (encoder_events.head + 1) % MAX_QUEUED_ENCODER_EVENTS;
+
+    return true;
+}
+
+void encoder_retrieve_events(encoder_events_t *events) {
+    memcpy(events, &encoder_events, sizeof(encoder_events));
+}
 
-static uint8_t encoder_value[NUM_ENCODERS] = {0};
+#ifdef SPLIT_KEYBOARD
+void encoder_set_tail_index(uint8_t tail_index) {
+    encoder_events.tail = tail_index;
+}
 
-__attribute__((weak)) void encoder_wait_pullup_charge(void) {
-    wait_us(100);
+void encoder_handle_slave_events(encoder_events_t *events) {
+    while (events->tail != events->head) {
+        encoder_event_t event = events->queue[events->tail];
+        events->tail          = (events->tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        encoder_queue_event(event.index, event.clockwise ? true : false);
+    }
 }
+#endif // SPLIT_KEYBOARD
 
 __attribute__((weak)) bool encoder_update_user(uint8_t index, bool clockwise) {
     return true;
@@ -106,192 +135,3 @@ __attribute__((weak)) bool encoder_update_kb(uint8_t index, bool clockwise) {
 #endif // ENCODER_TESTS
     return res;
 }
-
-__attribute__((weak)) bool should_process_encoder(void) {
-    return is_keyboard_master();
-}
-
-void encoder_init(void) {
-#ifdef SPLIT_KEYBOARD
-    thisHand  = isLeftHand ? 0 : NUM_ENCODERS_LEFT;
-    thatHand  = NUM_ENCODERS_LEFT - thisHand;
-    thisCount = isLeftHand ? NUM_ENCODERS_LEFT : NUM_ENCODERS_RIGHT;
-    thatCount = isLeftHand ? NUM_ENCODERS_RIGHT : NUM_ENCODERS_LEFT;
-#else // SPLIT_KEYBOARD
-    thisCount                = NUM_ENCODERS;
-#endif
-
-#ifdef ENCODER_TESTS
-    // Annoying that we have to clear out values during initialisation here, but
-    // because all the arrays are static locals, rerunning tests in the same
-    // executable doesn't reset any of these. Kinda crappy having test-only code
-    // here, but it's the simplest solution.
-    memset(encoder_value, 0, sizeof(encoder_value));
-    memset(encoder_state, 0, sizeof(encoder_state));
-    memset(encoder_pulses, 0, sizeof(encoder_pulses));
-    static const pin_t encoders_pad_a_left[] = ENCODERS_PAD_A;
-    static const pin_t encoders_pad_b_left[] = ENCODERS_PAD_B;
-    for (uint8_t i = 0; i < thisCount; i++) {
-        encoders_pad_a[i] = encoders_pad_a_left[i];
-        encoders_pad_b[i] = encoders_pad_b_left[i];
-    }
-#endif
-
-#if defined(SPLIT_KEYBOARD) && defined(ENCODERS_PAD_A_RIGHT) && defined(ENCODERS_PAD_B_RIGHT)
-    // Re-initialise the pads if it's the right-hand side
-    if (!isLeftHand) {
-        static const pin_t encoders_pad_a_right[] = ENCODERS_PAD_A_RIGHT;
-        static const pin_t encoders_pad_b_right[] = ENCODERS_PAD_B_RIGHT;
-        for (uint8_t i = 0; i < thisCount; i++) {
-            encoders_pad_a[i] = encoders_pad_a_right[i];
-            encoders_pad_b[i] = encoders_pad_b_right[i];
-        }
-    }
-#endif // defined(SPLIT_KEYBOARD) && defined(ENCODERS_PAD_A_RIGHT) && defined(ENCODERS_PAD_B_RIGHT)
-
-    // Encoder resolutions is handled purely master-side, so concatenate the two arrays
-#if defined(SPLIT_KEYBOARD) && defined(ENCODER_RESOLUTIONS)
-#    if defined(ENCODER_RESOLUTIONS_RIGHT)
-    static const uint8_t encoder_resolutions_right[NUM_ENCODERS_RIGHT] = ENCODER_RESOLUTIONS_RIGHT;
-#    else  // defined(ENCODER_RESOLUTIONS_RIGHT)
-    static const uint8_t encoder_resolutions_right[NUM_ENCODERS_RIGHT] = ENCODER_RESOLUTIONS;
-#    endif // defined(ENCODER_RESOLUTIONS_RIGHT)
-    for (uint8_t i = 0; i < NUM_ENCODERS_RIGHT; i++) {
-        encoder_resolutions[NUM_ENCODERS_LEFT + i] = encoder_resolutions_right[i];
-    }
-#endif // defined(SPLIT_KEYBOARD) && defined(ENCODER_RESOLUTIONS)
-
-    for (uint8_t i = 0; i < thisCount; i++) {
-        gpio_set_pin_input_high(encoders_pad_a[i]);
-        gpio_set_pin_input_high(encoders_pad_b[i]);
-    }
-    encoder_wait_pullup_charge();
-    for (uint8_t i = 0; i < thisCount; i++) {
-        encoder_state[i] = (gpio_read_pin(encoders_pad_a[i]) << 0) | (gpio_read_pin(encoders_pad_b[i]) << 1);
-    }
-}
-
-#ifdef ENCODER_MAP_ENABLE
-static void encoder_exec_mapping(uint8_t index, bool clockwise) {
-    // The delays below cater for Windows and its wonderful requirements.
-    action_exec(clockwise ? MAKE_ENCODER_CW_EVENT(index, true) : MAKE_ENCODER_CCW_EVENT(index, true));
-#    if ENCODER_MAP_KEY_DELAY > 0
-    wait_ms(ENCODER_MAP_KEY_DELAY);
-#    endif // ENCODER_MAP_KEY_DELAY > 0
-
-    action_exec(clockwise ? MAKE_ENCODER_CW_EVENT(index, false) : MAKE_ENCODER_CCW_EVENT(index, false));
-#    if ENCODER_MAP_KEY_DELAY > 0
-    wait_ms(ENCODER_MAP_KEY_DELAY);
-#    endif // ENCODER_MAP_KEY_DELAY > 0
-}
-#endif // ENCODER_MAP_ENABLE
-
-static bool encoder_update(uint8_t index, uint8_t state) {
-    bool    changed = false;
-    uint8_t i       = index;
-
-#ifdef ENCODER_RESOLUTIONS
-    const uint8_t resolution = encoder_resolutions[i];
-#else
-    const uint8_t resolution = ENCODER_RESOLUTION;
-#endif
-
-#ifdef SPLIT_KEYBOARD
-    index += thisHand;
-#endif
-    encoder_pulses[i] += encoder_LUT[state & 0xF];
-
-#ifdef ENCODER_DEFAULT_POS
-    if ((encoder_pulses[i] >= resolution) || (encoder_pulses[i] <= -resolution) || ((state & 0x3) == ENCODER_DEFAULT_POS)) {
-        if (encoder_pulses[i] >= 1) {
-#else
-    if (encoder_pulses[i] >= resolution) {
-#endif
-
-            encoder_value[index]++;
-            changed = true;
-#ifdef SPLIT_KEYBOARD
-            if (should_process_encoder())
-#endif // SPLIT_KEYBOARD
-#ifdef ENCODER_MAP_ENABLE
-                encoder_exec_mapping(index, ENCODER_COUNTER_CLOCKWISE);
-#else  // ENCODER_MAP_ENABLE
-        encoder_update_kb(index, ENCODER_COUNTER_CLOCKWISE);
-#endif // ENCODER_MAP_ENABLE
-        }
-
-#ifdef ENCODER_DEFAULT_POS
-        if (encoder_pulses[i] <= -1) {
-#else
-    if (encoder_pulses[i] <= -resolution) { // direction is arbitrary here, but this clockwise
-#endif
-            encoder_value[index]--;
-            changed = true;
-#ifdef SPLIT_KEYBOARD
-            if (should_process_encoder())
-#endif // SPLIT_KEYBOARD
-#ifdef ENCODER_MAP_ENABLE
-                encoder_exec_mapping(index, ENCODER_CLOCKWISE);
-#else  // ENCODER_MAP_ENABLE
-        encoder_update_kb(index, ENCODER_CLOCKWISE);
-#endif // ENCODER_MAP_ENABLE
-        }
-        encoder_pulses[i] %= resolution;
-#ifdef ENCODER_DEFAULT_POS
-        encoder_pulses[i] = 0;
-    }
-#endif
-    return changed;
-}
-
-bool encoder_read(void) {
-    bool changed = false;
-    for (uint8_t i = 0; i < thisCount; i++) {
-        uint8_t new_status = (gpio_read_pin(encoders_pad_a[i]) << 0) | (gpio_read_pin(encoders_pad_b[i]) << 1);
-        if ((encoder_state[i] & 0x3) != new_status) {
-            encoder_state[i] <<= 2;
-            encoder_state[i] |= new_status;
-            changed |= encoder_update(i, encoder_state[i]);
-        }
-    }
-    return changed;
-}
-
-#ifdef SPLIT_KEYBOARD
-void last_encoder_activity_trigger(void);
-
-void encoder_state_raw(uint8_t *slave_state) {
-    memcpy(slave_state, &encoder_value[thisHand], sizeof(uint8_t) * thisCount);
-}
-
-void encoder_update_raw(uint8_t *slave_state) {
-    bool changed = false;
-    for (uint8_t i = 0; i < thatCount; i++) { // Note inverted logic -- we want the opposite side
-        const uint8_t index = i + thatHand;
-        int8_t        delta = slave_state[i] - encoder_value[index];
-        while (delta > 0) {
-            delta--;
-            encoder_value[index]++;
-            changed = true;
-#    ifdef ENCODER_MAP_ENABLE
-            encoder_exec_mapping(index, ENCODER_COUNTER_CLOCKWISE);
-#    else  // ENCODER_MAP_ENABLE
-            encoder_update_kb(index, ENCODER_COUNTER_CLOCKWISE);
-#    endif // ENCODER_MAP_ENABLE
-        }
-        while (delta < 0) {
-            delta++;
-            encoder_value[index]--;
-            changed = true;
-#    ifdef ENCODER_MAP_ENABLE
-            encoder_exec_mapping(index, ENCODER_CLOCKWISE);
-#    else  // ENCODER_MAP_ENABLE
-            encoder_update_kb(index, ENCODER_CLOCKWISE);
-#    endif // ENCODER_MAP_ENABLE
-        }
-    }
-
-    // Update the last encoder input time -- handled external to encoder_read() when we're running a split
-    if (changed) last_encoder_activity_trigger();
-}
-#endif
diff --git a/quantum/encoder.h b/quantum/encoder.h
index 1cbac98cb5..90414a43a0 100644
--- a/quantum/encoder.h
+++ b/quantum/encoder.h
@@ -22,45 +22,88 @@
 #include "gpio.h"
 #include "util.h"
 
+#ifdef ENCODER_ENABLE
+
+__attribute__((weak)) bool should_process_encoder(void);
+
 void encoder_init(void);
-bool encoder_read(void);
+bool encoder_task(void);
+bool encoder_queue_event(uint8_t index, bool clockwise);
 
 bool encoder_update_kb(uint8_t index, bool clockwise);
 bool encoder_update_user(uint8_t index, bool clockwise);
 
-#ifdef SPLIT_KEYBOARD
+#    ifdef SPLIT_KEYBOARD
+
+#        if defined(ENCODERS_PAD_A_RIGHT)
+#            ifndef NUM_ENCODERS_LEFT
+#                define NUM_ENCODERS_LEFT ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A))
+#            endif
+#            ifndef NUM_ENCODERS_RIGHT
+#                define NUM_ENCODERS_RIGHT ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A_RIGHT))
+#            endif
+#        else
+#            ifndef NUM_ENCODERS_LEFT
+#                define NUM_ENCODERS_LEFT ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A))
+#            endif
+#            ifndef NUM_ENCODERS_RIGHT
+#                define NUM_ENCODERS_RIGHT NUM_ENCODERS_LEFT
+#            endif
+#        endif
+#        ifndef NUM_ENCODERS
+#            define NUM_ENCODERS (NUM_ENCODERS_LEFT + NUM_ENCODERS_RIGHT)
+#        endif
+
+#    else // SPLIT_KEYBOARD
 
-void encoder_state_raw(uint8_t* slave_state);
-void encoder_update_raw(uint8_t* slave_state);
+#        ifndef NUM_ENCODERS
+#            define NUM_ENCODERS ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A))
+#        endif
+#        define NUM_ENCODERS_LEFT NUM_ENCODERS
+#        define NUM_ENCODERS_RIGHT 0
 
-#    if defined(ENCODERS_PAD_A_RIGHT)
-#        define NUM_ENCODERS_LEFT ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A))
-#        define NUM_ENCODERS_RIGHT ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A_RIGHT))
-#    else
-#        define NUM_ENCODERS_LEFT ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A))
-#        define NUM_ENCODERS_RIGHT NUM_ENCODERS_LEFT
-#    endif
-#    define NUM_ENCODERS (NUM_ENCODERS_LEFT + NUM_ENCODERS_RIGHT)
+#    endif // SPLIT_KEYBOARD
 
-#else // SPLIT_KEYBOARD
+#    ifndef NUM_ENCODERS
+#        define NUM_ENCODERS 0
+#        define NUM_ENCODERS_LEFT 0
+#        define NUM_ENCODERS_RIGHT 0
+#    endif // NUM_ENCODERS
 
-#    define NUM_ENCODERS ARRAY_SIZE(((pin_t[])ENCODERS_PAD_A))
-#    define NUM_ENCODERS_LEFT NUM_ENCODERS
-#    define NUM_ENCODERS_RIGHT 0
+#    define NUM_ENCODERS_MAX_PER_SIDE MAX(NUM_ENCODERS_LEFT, NUM_ENCODERS_RIGHT)
 
-#endif // SPLIT_KEYBOARD
+#    ifndef MAX_QUEUED_ENCODER_EVENTS
+#        define MAX_QUEUED_ENCODER_EVENTS MAX(4, ((NUM_ENCODERS_MAX_PER_SIDE) + 1))
+#    endif // MAX_QUEUED_ENCODER_EVENTS
 
-#ifndef NUM_ENCODERS
-#    define NUM_ENCODERS 0
-#    define NUM_ENCODERS_LEFT 0
-#    define NUM_ENCODERS_RIGHT 0
-#endif // NUM_ENCODERS
+typedef struct encoder_event_t {
+    uint8_t index : 7;
+    uint8_t clockwise : 1;
+} encoder_event_t;
 
-#define NUM_ENCODERS_MAX_PER_SIDE MAX(NUM_ENCODERS_LEFT, NUM_ENCODERS_RIGHT)
+typedef struct encoder_events_t {
+    uint8_t         head;
+    uint8_t         tail;
+    encoder_event_t queue[MAX_QUEUED_ENCODER_EVENTS];
+} encoder_events_t;
 
-#ifdef ENCODER_MAP_ENABLE
-#    define NUM_DIRECTIONS 2
-#    define ENCODER_CCW_CW(ccw, cw) \
-        { (cw), (ccw) }
+// Get the current queued events
+void encoder_retrieve_events(encoder_events_t *events);
+
+#    ifdef SPLIT_KEYBOARD
+void encoder_set_tail_index(uint8_t tail_index);
+void encoder_handle_slave_events(encoder_events_t *events);
+#    endif // SPLIT_KEYBOARD
+
+#    ifdef ENCODER_MAP_ENABLE
+#        define NUM_DIRECTIONS 2
+#        define ENCODER_CCW_CW(ccw, cw) \
+            { (cw), (ccw) }
 extern const uint16_t encoder_map[][NUM_ENCODERS][NUM_DIRECTIONS];
-#endif // ENCODER_MAP_ENABLE
+#    endif // ENCODER_MAP_ENABLE
+
+// "Custom encoder lite" support
+void encoder_driver_init(void);
+void encoder_driver_task(void);
+
+#endif // ENCODER_ENABLE
diff --git a/quantum/encoder/tests/config_encoder_common.h b/quantum/encoder/tests/config_encoder_common.h
new file mode 100644
index 0000000000..6b3b20182b
--- /dev/null
+++ b/quantum/encoder/tests/config_encoder_common.h
@@ -0,0 +1,6 @@
+// Copyright 2023 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+#pragma once
+
+// Override the one in quantum/util because it doesn't like working on x64 builds.
+#define ARRAY_SIZE(array) (sizeof((array)) / sizeof((array)[0]))
diff --git a/quantum/encoder/tests/config_mock.h b/quantum/encoder/tests/config_mock.h
index 703dcaf103..9eb59ddc88 100644
--- a/quantum/encoder/tests/config_mock.h
+++ b/quantum/encoder/tests/config_mock.h
@@ -1,6 +1,7 @@
-// Copyright 2022 Nick Brassel (@tzarc)
+// Copyright 2022-2023 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
+#include "config_encoder_common.h"
 
 #define MATRIX_ROWS 1
 #define MATRIX_COLS 1
diff --git a/quantum/encoder/tests/config_mock_split_left_eq_right.h b/quantum/encoder/tests/config_mock_split_left_eq_right.h
index c80ac4d519..ea795657ef 100644
--- a/quantum/encoder/tests/config_mock_split_left_eq_right.h
+++ b/quantum/encoder/tests/config_mock_split_left_eq_right.h
@@ -1,6 +1,7 @@
-// Copyright 2022 Nick Brassel (@tzarc)
+// Copyright 2022-2023 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
+#include "config_encoder_common.h"
 
 #define MATRIX_ROWS 1
 #define MATRIX_COLS 1
diff --git a/quantum/encoder/tests/config_mock_split_left_gt_right.h b/quantum/encoder/tests/config_mock_split_left_gt_right.h
index 91d5f3d605..abcfe03918 100644
--- a/quantum/encoder/tests/config_mock_split_left_gt_right.h
+++ b/quantum/encoder/tests/config_mock_split_left_gt_right.h
@@ -1,6 +1,7 @@
-// Copyright 2022 Nick Brassel (@tzarc)
+// Copyright 2022-2023 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
+#include "config_encoder_common.h"
 
 #define MATRIX_ROWS 1
 #define MATRIX_COLS 1
diff --git a/quantum/encoder/tests/config_mock_split_left_lt_right.h b/quantum/encoder/tests/config_mock_split_left_lt_right.h
index 4108a184a6..075c774b0d 100644
--- a/quantum/encoder/tests/config_mock_split_left_lt_right.h
+++ b/quantum/encoder/tests/config_mock_split_left_lt_right.h
@@ -1,6 +1,7 @@
-// Copyright 2022 Nick Brassel (@tzarc)
+// Copyright 2022-2023 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
+#include "config_encoder_common.h"
 
 #define MATRIX_ROWS 1
 #define MATRIX_COLS 1
diff --git a/quantum/encoder/tests/config_mock_split_no_left.h b/quantum/encoder/tests/config_mock_split_no_left.h
index 9db7fa7e41..dfd8358929 100644
--- a/quantum/encoder/tests/config_mock_split_no_left.h
+++ b/quantum/encoder/tests/config_mock_split_no_left.h
@@ -1,6 +1,7 @@
-// Copyright 2022 Nick Brassel (@tzarc)
+// Copyright 2022-2023 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
+#include "config_encoder_common.h"
 
 #define MATRIX_ROWS 1
 #define MATRIX_COLS 1
diff --git a/quantum/encoder/tests/config_mock_split_no_right.h b/quantum/encoder/tests/config_mock_split_no_right.h
index 14f18015e6..5683eade8c 100644
--- a/quantum/encoder/tests/config_mock_split_no_right.h
+++ b/quantum/encoder/tests/config_mock_split_no_right.h
@@ -1,6 +1,7 @@
-// Copyright 2022 Nick Brassel (@tzarc)
+// Copyright 2022-2023 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
+#include "config_encoder_common.h"
 
 #define MATRIX_ROWS 1
 #define MATRIX_COLS 1
diff --git a/quantum/encoder/tests/config_mock_split_role.h b/quantum/encoder/tests/config_mock_split_role.h
index c80ac4d519..ea795657ef 100644
--- a/quantum/encoder/tests/config_mock_split_role.h
+++ b/quantum/encoder/tests/config_mock_split_role.h
@@ -1,6 +1,7 @@
-// Copyright 2022 Nick Brassel (@tzarc)
+// Copyright 2022-2023 Nick Brassel (@tzarc)
 // SPDX-License-Identifier: GPL-2.0-or-later
 #pragma once
+#include "config_encoder_common.h"
 
 #define MATRIX_ROWS 1
 #define MATRIX_COLS 1
diff --git a/quantum/encoder/tests/encoder_tests.cpp b/quantum/encoder/tests/encoder_tests.cpp
index b7c18aeec0..499e413aed 100644
--- a/quantum/encoder/tests/encoder_tests.cpp
+++ b/quantum/encoder/tests/encoder_tests.cpp
@@ -41,7 +41,7 @@ bool encoder_update_kb(uint8_t index, bool clockwise) {
 
 bool setAndRead(pin_t pin, bool val) {
     setPin(pin, val);
-    return encoder_read();
+    return encoder_task();
 }
 
 class EncoderTest : public ::testing::Test {};
diff --git a/quantum/encoder/tests/encoder_tests_split_left_eq_right.cpp b/quantum/encoder/tests/encoder_tests_split_left_eq_right.cpp
index 916e47b185..7d6b3e30e6 100644
--- a/quantum/encoder/tests/encoder_tests_split_left_eq_right.cpp
+++ b/quantum/encoder/tests/encoder_tests_split_left_eq_right.cpp
@@ -33,22 +33,29 @@ struct update {
 uint8_t updates_array_idx = 0;
 update  updates[32];
 
+bool isMaster;
 bool isLeftHand;
 
+extern "C" {
+bool is_keyboard_master(void) {
+    return isMaster;
+}
+
 bool encoder_update_kb(uint8_t index, bool clockwise) {
-    if (!isLeftHand) {
+    if (!is_keyboard_master()) {
         // this method has no effect on slave half
-        printf("ignoring update on right hand (%d,%s)\n", index, clockwise ? "CW" : "CC");
+        printf("ignoring update on slave (%d,%s)\n", index, clockwise ? "CW" : "CC");
         return true;
     }
     updates[updates_array_idx % 32] = {index, clockwise};
     updates_array_idx++;
     return true;
 }
+};
 
 bool setAndRead(pin_t pin, bool val) {
     setPin(pin, val);
-    return encoder_read();
+    return encoder_task();
 }
 
 class EncoderSplitTestLeftEqRight : public ::testing::Test {
@@ -63,6 +70,7 @@ class EncoderSplitTestLeftEqRight : public ::testing::Test {
 };
 
 TEST_F(EncoderSplitTestLeftEqRight, TestInitLeft) {
+    isMaster   = true;
     isLeftHand = true;
     encoder_init();
     EXPECT_EQ(pinIsInputHigh[0], true);
@@ -77,6 +85,7 @@ TEST_F(EncoderSplitTestLeftEqRight, TestInitLeft) {
 }
 
 TEST_F(EncoderSplitTestLeftEqRight, TestInitRight) {
+    isMaster   = true;
     isLeftHand = false;
     encoder_init();
     EXPECT_EQ(pinIsInputHigh[0], false);
@@ -90,7 +99,8 @@ TEST_F(EncoderSplitTestLeftEqRight, TestInitRight) {
     EXPECT_EQ(updates_array_idx, 0); // no updates received
 }
 
-TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseLeft) {
+TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseLeftMaster) {
+    isMaster   = true;
     isLeftHand = true;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
@@ -102,9 +112,19 @@ TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseLeft) {
     EXPECT_EQ(updates_array_idx, 1); // one update received
     EXPECT_EQ(updates[0].index, 0);
     EXPECT_EQ(updates[0].clockwise, true);
+
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseRightSent) {
+TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseRightMaster) {
+    isMaster   = true;
     isLeftHand = false;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
@@ -113,23 +133,60 @@ TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseRightSent) {
     setAndRead(6, true);
     setAndRead(7, true);
 
-    uint8_t slave_state[32] = {0};
-    encoder_state_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 1); // one update received
+    EXPECT_EQ(updates[0].index, 3);
+    EXPECT_EQ(updates[0].clockwise, true);
 
-    EXPECT_EQ(slave_state[0], 0);
-    EXPECT_EQ(slave_state[1], 0xFF);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestLeftEqRight, TestMultipleEncodersRightReceived) {
+TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseLeftSlave) {
+    isMaster   = false;
     isLeftHand = true;
     encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
 
-    uint8_t slave_state[32] = {1, 0xFF}; // First right encoder is CCW, Second right encoder CW
-    encoder_update_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
 
-    EXPECT_EQ(updates_array_idx, 2); // two updates received, one for each changed item on the right side
-    EXPECT_EQ(updates[0].index, 2);
-    EXPECT_EQ(updates[0].clockwise, false);
-    EXPECT_EQ(updates[1].index, 3);
-    EXPECT_EQ(updates[1].clockwise, true);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
+}
+
+TEST_F(EncoderSplitTestLeftEqRight, TestOneClockwiseRightSlave) {
+    isMaster   = false;
+    isLeftHand = false;
+    encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(6, false);
+    setAndRead(7, false);
+    setAndRead(6, true);
+    setAndRead(7, true);
+
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
+
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
 }
diff --git a/quantum/encoder/tests/encoder_tests_split_left_gt_right.cpp b/quantum/encoder/tests/encoder_tests_split_left_gt_right.cpp
index 7b64bb2981..2beb4e3972 100644
--- a/quantum/encoder/tests/encoder_tests_split_left_gt_right.cpp
+++ b/quantum/encoder/tests/encoder_tests_split_left_gt_right.cpp
@@ -33,22 +33,29 @@ struct update {
 uint8_t updates_array_idx = 0;
 update  updates[32];
 
+bool isMaster;
 bool isLeftHand;
 
+extern "C" {
+bool is_keyboard_master(void) {
+    return isMaster;
+}
+
 bool encoder_update_kb(uint8_t index, bool clockwise) {
-    if (!isLeftHand) {
+    if (!is_keyboard_master()) {
         // this method has no effect on slave half
-        printf("ignoring update on right hand (%d,%s)\n", index, clockwise ? "CW" : "CC");
+        printf("ignoring update on slave (%d,%s)\n", index, clockwise ? "CW" : "CC");
         return true;
     }
     updates[updates_array_idx % 32] = {index, clockwise};
     updates_array_idx++;
     return true;
 }
+};
 
 bool setAndRead(pin_t pin, bool val) {
     setPin(pin, val);
-    return encoder_read();
+    return encoder_task();
 }
 
 class EncoderSplitTestLeftGreaterThanRight : public ::testing::Test {
@@ -94,7 +101,8 @@ TEST_F(EncoderSplitTestLeftGreaterThanRight, TestInitRight) {
     EXPECT_EQ(updates_array_idx, 0); // no updates received
 }
 
-TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseLeft) {
+TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseLeftMaster) {
+    isMaster   = true;
     isLeftHand = true;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
@@ -106,9 +114,19 @@ TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseLeft) {
     EXPECT_EQ(updates_array_idx, 1); // one update received
     EXPECT_EQ(updates[0].index, 0);
     EXPECT_EQ(updates[0].clockwise, true);
+
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseRightSent) {
+TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseRightMaster) {
+    isMaster   = true;
     isLeftHand = false;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
@@ -117,23 +135,60 @@ TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseRightSent) {
     setAndRead(6, true);
     setAndRead(7, true);
 
-    uint8_t slave_state[32] = {0};
-    encoder_state_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 1); // one update received
+    EXPECT_EQ(updates[0].index, 3);
+    EXPECT_EQ(updates[0].clockwise, true);
 
-    EXPECT_EQ(slave_state[0], 0xFF);
-    EXPECT_EQ(slave_state[1], 0);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestLeftGreaterThanRight, TestMultipleEncodersRightReceived) {
+TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseLeftSlave) {
+    isMaster   = false;
     isLeftHand = true;
     encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
 
-    uint8_t slave_state[32] = {1, 0xFF}; // First right encoder is CCW, Second right encoder no change, third right encoder CW
-    encoder_update_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
 
-    EXPECT_EQ(updates_array_idx, 2); // two updates received, one for each changed item on the right side
-    EXPECT_EQ(updates[0].index, 3);
-    EXPECT_EQ(updates[0].clockwise, false);
-    EXPECT_EQ(updates[1].index, 4);
-    EXPECT_EQ(updates[1].clockwise, true);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
+}
+
+TEST_F(EncoderSplitTestLeftGreaterThanRight, TestOneClockwiseRightSlave) {
+    isMaster   = false;
+    isLeftHand = false;
+    encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(6, false);
+    setAndRead(7, false);
+    setAndRead(6, true);
+    setAndRead(7, true);
+
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
+
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
 }
diff --git a/quantum/encoder/tests/encoder_tests_split_left_lt_right.cpp b/quantum/encoder/tests/encoder_tests_split_left_lt_right.cpp
index a6519c5762..5612f8b658 100644
--- a/quantum/encoder/tests/encoder_tests_split_left_lt_right.cpp
+++ b/quantum/encoder/tests/encoder_tests_split_left_lt_right.cpp
@@ -33,22 +33,29 @@ struct update {
 uint8_t updates_array_idx = 0;
 update  updates[32];
 
+bool isMaster;
 bool isLeftHand;
 
+extern "C" {
+bool is_keyboard_master(void) {
+    return isMaster;
+}
+
 bool encoder_update_kb(uint8_t index, bool clockwise) {
-    if (!isLeftHand) {
+    if (!is_keyboard_master()) {
         // this method has no effect on slave half
-        printf("ignoring update on right hand (%d,%s)\n", index, clockwise ? "CW" : "CC");
+        printf("ignoring update on slave (%d,%s)\n", index, clockwise ? "CW" : "CC");
         return true;
     }
     updates[updates_array_idx % 32] = {index, clockwise};
     updates_array_idx++;
     return true;
 }
+};
 
 bool setAndRead(pin_t pin, bool val) {
     setPin(pin, val);
-    return encoder_read();
+    return encoder_task();
 }
 
 class EncoderSplitTestLeftLessThanRight : public ::testing::Test {
@@ -94,7 +101,8 @@ TEST_F(EncoderSplitTestLeftLessThanRight, TestInitRight) {
     EXPECT_EQ(updates_array_idx, 0); // no updates received
 }
 
-TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseLeft) {
+TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseLeftMaster) {
+    isMaster   = true;
     isLeftHand = true;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
@@ -106,9 +114,19 @@ TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseLeft) {
     EXPECT_EQ(updates_array_idx, 1); // one update received
     EXPECT_EQ(updates[0].index, 0);
     EXPECT_EQ(updates[0].clockwise, true);
+
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseRightSent) {
+TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseRightMaster) {
+    isMaster   = true;
     isLeftHand = false;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
@@ -117,23 +135,60 @@ TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseRightSent) {
     setAndRead(6, true);
     setAndRead(7, true);
 
-    uint8_t slave_state[32] = {0};
-    encoder_state_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 1); // one update received
+    EXPECT_EQ(updates[0].index, 3);
+    EXPECT_EQ(updates[0].clockwise, true);
 
-    EXPECT_EQ(slave_state[0], 0);
-    EXPECT_EQ(slave_state[1], 0xFF);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestLeftLessThanRight, TestMultipleEncodersRightReceived) {
+TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseLeftSlave) {
+    isMaster   = false;
     isLeftHand = true;
     encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(0, false);
+    setAndRead(1, false);
+    setAndRead(0, true);
+    setAndRead(1, true);
 
-    uint8_t slave_state[32] = {1, 0, 0xFF}; // First right encoder is CCW, Second right encoder no change, third right encoder CW
-    encoder_update_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
 
-    EXPECT_EQ(updates_array_idx, 2); // two updates received, one for each changed item on the right side
-    EXPECT_EQ(updates[0].index, 2);
-    EXPECT_EQ(updates[0].clockwise, false);
-    EXPECT_EQ(updates[1].index, 4);
-    EXPECT_EQ(updates[1].clockwise, true);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
+}
+
+TEST_F(EncoderSplitTestLeftLessThanRight, TestOneClockwiseRightSlave) {
+    isMaster   = false;
+    isLeftHand = false;
+    encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(6, false);
+    setAndRead(7, false);
+    setAndRead(6, true);
+    setAndRead(7, true);
+
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
+
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
 }
diff --git a/quantum/encoder/tests/encoder_tests_split_no_left.cpp b/quantum/encoder/tests/encoder_tests_split_no_left.cpp
index b6b2d7e2d1..980e4074ff 100644
--- a/quantum/encoder/tests/encoder_tests_split_no_left.cpp
+++ b/quantum/encoder/tests/encoder_tests_split_no_left.cpp
@@ -33,22 +33,29 @@ struct update {
 uint8_t updates_array_idx = 0;
 update  updates[32];
 
+bool isMaster;
 bool isLeftHand;
 
+extern "C" {
+bool is_keyboard_master(void) {
+    return isMaster;
+}
+
 bool encoder_update_kb(uint8_t index, bool clockwise) {
-    if (!isLeftHand) {
+    if (!is_keyboard_master()) {
         // this method has no effect on slave half
-        printf("ignoring update on right hand (%d,%s)\n", index, clockwise ? "CW" : "CC");
+        printf("ignoring update on slave (%d,%s)\n", index, clockwise ? "CW" : "CC");
         return true;
     }
     updates[updates_array_idx % 32] = {index, clockwise};
     updates_array_idx++;
     return true;
 }
+};
 
 bool setAndRead(pin_t pin, bool val) {
     setPin(pin, val);
-    return encoder_read();
+    return encoder_task();
 }
 
 class EncoderSplitTestNoLeft : public ::testing::Test {
@@ -82,19 +89,8 @@ TEST_F(EncoderSplitTestNoLeft, TestInitRight) {
     EXPECT_EQ(updates_array_idx, 0); // no updates received
 }
 
-TEST_F(EncoderSplitTestNoLeft, TestOneClockwiseLeft) {
-    isLeftHand = true;
-    encoder_init();
-    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
-    setAndRead(0, false);
-    setAndRead(1, false);
-    setAndRead(0, true);
-    setAndRead(1, true);
-
-    EXPECT_EQ(updates_array_idx, 0); // no updates received
-}
-
-TEST_F(EncoderSplitTestNoLeft, TestOneClockwiseRightSent) {
+TEST_F(EncoderSplitTestNoLeft, TestOneClockwiseLeftMaster) {
+    isMaster   = true;
     isLeftHand = false;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
@@ -103,23 +99,38 @@ TEST_F(EncoderSplitTestNoLeft, TestOneClockwiseRightSent) {
     setAndRead(2, true);
     setAndRead(3, true);
 
-    uint8_t slave_state[32] = {0};
-    encoder_state_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 1); // one update received
+    EXPECT_EQ(updates[0].index, 1);
+    EXPECT_EQ(updates[0].clockwise, true);
 
-    EXPECT_EQ(slave_state[0], 0);
-    EXPECT_EQ(slave_state[1], 0xFF);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestNoLeft, TestMultipleEncodersRightReceived) {
-    isLeftHand = true;
+TEST_F(EncoderSplitTestNoLeft, TestOneClockwiseRightSlave) {
+    isMaster   = false;
+    isLeftHand = false;
     encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(2, false);
+    setAndRead(3, false);
+    setAndRead(2, true);
+    setAndRead(3, true);
 
-    uint8_t slave_state[32] = {1, 0xFF}; // First right encoder is CCW, Second right encoder no change, third right encoder CW
-    encoder_update_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
 
-    EXPECT_EQ(updates_array_idx, 2); // two updates received, one for each changed item on the right side
-    EXPECT_EQ(updates[0].index, 0);
-    EXPECT_EQ(updates[0].clockwise, false);
-    EXPECT_EQ(updates[1].index, 1);
-    EXPECT_EQ(updates[1].clockwise, true);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
 }
diff --git a/quantum/encoder/tests/encoder_tests_split_no_right.cpp b/quantum/encoder/tests/encoder_tests_split_no_right.cpp
index fa0a7c18a8..d39659853b 100644
--- a/quantum/encoder/tests/encoder_tests_split_no_right.cpp
+++ b/quantum/encoder/tests/encoder_tests_split_no_right.cpp
@@ -33,22 +33,29 @@ struct update {
 uint8_t updates_array_idx = 0;
 update  updates[32];
 
+bool isMaster;
 bool isLeftHand;
 
+extern "C" {
+bool is_keyboard_master(void) {
+    return isMaster;
+}
+
 bool encoder_update_kb(uint8_t index, bool clockwise) {
-    if (!isLeftHand) {
+    if (!is_keyboard_master()) {
         // this method has no effect on slave half
-        printf("ignoring update on right hand (%d,%s)\n", index, clockwise ? "CW" : "CC");
+        printf("ignoring update on slave (%d,%s)\n", index, clockwise ? "CW" : "CC");
         return true;
     }
     updates[updates_array_idx % 32] = {index, clockwise};
     updates_array_idx++;
     return true;
 }
+};
 
 bool setAndRead(pin_t pin, bool val) {
     setPin(pin, val);
-    return encoder_read();
+    return encoder_task();
 }
 
 class EncoderSplitTestNoRight : public ::testing::Test {
@@ -82,37 +89,48 @@ TEST_F(EncoderSplitTestNoRight, TestInitRight) {
     EXPECT_EQ(updates_array_idx, 0); // no updates received
 }
 
-TEST_F(EncoderSplitTestNoRight, TestOneClockwiseLeft) {
+TEST_F(EncoderSplitTestNoRight, TestOneClockwiseLeftMaster) {
+    isMaster   = true;
     isLeftHand = true;
     encoder_init();
     // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
-    setAndRead(0, false);
-    setAndRead(1, false);
-    setAndRead(0, true);
-    setAndRead(1, true);
+    setAndRead(2, false);
+    setAndRead(3, false);
+    setAndRead(2, true);
+    setAndRead(3, true);
 
-    EXPECT_EQ(updates_array_idx, 1); // one updates received
-    EXPECT_EQ(updates[0].index, 0);
+    EXPECT_EQ(updates_array_idx, 1); // one update received
+    EXPECT_EQ(updates[0].index, 1);
     EXPECT_EQ(updates[0].clockwise, true);
-}
 
-TEST_F(EncoderSplitTestNoRight, TestOneClockwiseRightSent) {
-    isLeftHand = false;
-    encoder_init();
-
-    uint8_t slave_state[32] = {0xAA, 0xAA};
-    encoder_state_raw(slave_state);
-
-    EXPECT_EQ(slave_state[0], 0xAA);
-    EXPECT_EQ(slave_state[1], 0xAA);
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 0); // No events should be queued on master
 }
 
-TEST_F(EncoderSplitTestNoRight, TestMultipleEncodersRightReceived) {
+TEST_F(EncoderSplitTestNoRight, TestOneClockwiseRightSlave) {
+    isMaster   = false;
     isLeftHand = true;
     encoder_init();
+    // send 4 pulses. with resolution 4, that's one step and we should get 1 update.
+    setAndRead(2, false);
+    setAndRead(3, false);
+    setAndRead(2, true);
+    setAndRead(3, true);
 
-    uint8_t slave_state[32] = {1, 0xFF}; // These values would trigger updates if there were encoders on the other side
-    encoder_update_raw(slave_state);
+    EXPECT_EQ(updates_array_idx, 0); // no updates received
 
-    EXPECT_EQ(updates_array_idx, 0); // no updates received -- no right-hand encoders
+    int              events_queued = 0;
+    encoder_events_t events;
+    encoder_retrieve_events(&events);
+    while (events.tail != events.head) {
+        events.tail = (events.tail + 1) % MAX_QUEUED_ENCODER_EVENTS;
+        ++events_queued;
+    }
+    EXPECT_EQ(events_queued, 1); // One event should be queued on slave
 }
diff --git a/quantum/encoder/tests/encoder_tests_split_role.cpp b/quantum/encoder/tests/encoder_tests_split_role.cpp
index 0ab7bfc2a7..b588af8c70 100644
--- a/quantum/encoder/tests/encoder_tests_split_role.cpp
+++ b/quantum/encoder/tests/encoder_tests_split_role.cpp
@@ -50,7 +50,7 @@ bool encoder_update_kb(uint8_t index, bool clockwise) {
 
 bool setAndRead(pin_t pin, bool val) {
     setPin(pin, val);
-    return encoder_read();
+    return encoder_task();
 }
 
 class EncoderSplitTestRole : public ::testing::Test {
@@ -87,9 +87,6 @@ TEST_F(EncoderSplitTestRole, TestPrimaryRight) {
     setAndRead(6, true);
     setAndRead(7, true);
 
-    uint8_t slave_state[32] = {0};
-    encoder_state_raw(slave_state);
-
     EXPECT_EQ(num_updates, 1); // one update received
 }
 
@@ -116,8 +113,5 @@ TEST_F(EncoderSplitTestRole, TestNotPrimaryRight) {
     setAndRead(6, true);
     setAndRead(7, true);
 
-    uint8_t slave_state[32] = {0};
-    encoder_state_raw(slave_state);
-
     EXPECT_EQ(num_updates, 0); // zero updates received
 }
diff --git a/quantum/encoder/tests/mock_split.c b/quantum/encoder/tests/mock_split.c
index f024c2058d..fb5f074fbb 100644
--- a/quantum/encoder/tests/mock_split.c
+++ b/quantum/encoder/tests/mock_split.c
@@ -36,7 +36,3 @@ bool setPin(pin_t pin, bool val) {
 }
 
 void last_encoder_activity_trigger(void) {}
-
-__attribute__((weak)) bool is_keyboard_master(void) {
-    return true;
-}
diff --git a/quantum/encoder/tests/mock_split.h b/quantum/encoder/tests/mock_split.h
index 8b4a141078..0d108afa6e 100644
--- a/quantum/encoder/tests/mock_split.h
+++ b/quantum/encoder/tests/mock_split.h
@@ -22,9 +22,6 @@
 #define SPLIT_KEYBOARD
 typedef uint8_t pin_t;
 
-void encoder_state_raw(uint8_t* slave_state);
-void encoder_update_raw(uint8_t* slave_state);
-
 extern bool pins[];
 extern bool pinIsInputHigh[];
 
diff --git a/quantum/encoder/tests/rules.mk b/quantum/encoder/tests/rules.mk
index d01c1c66ee..eb6106039e 100644
--- a/quantum/encoder/tests/rules.mk
+++ b/quantum/encoder/tests/rules.mk
@@ -3,6 +3,7 @@ encoder_CONFIG := $(QUANTUM_PATH)/encoder/tests/config_mock.h
 
 encoder_SRC := \
 	platforms/test/timer.c \
+	drivers/encoder/encoder_quadrature.c \
 	$(QUANTUM_PATH)/encoder/tests/mock.c \
 	$(QUANTUM_PATH)/encoder/tests/encoder_tests.cpp \
 	$(QUANTUM_PATH)/encoder.c
@@ -13,6 +14,7 @@ encoder_split_left_eq_right_CONFIG := $(QUANTUM_PATH)/encoder/tests/config_mock_
 
 encoder_split_left_eq_right_SRC := \
 	platforms/test/timer.c \
+	drivers/encoder/encoder_quadrature.c \
 	$(QUANTUM_PATH)/encoder/tests/mock_split.c \
 	$(QUANTUM_PATH)/encoder/tests/encoder_tests_split_left_eq_right.cpp \
 	$(QUANTUM_PATH)/encoder.c
@@ -23,6 +25,7 @@ encoder_split_left_gt_right_CONFIG := $(QUANTUM_PATH)/encoder/tests/config_mock_
 
 encoder_split_left_gt_right_SRC := \
 	platforms/test/timer.c \
+	drivers/encoder/encoder_quadrature.c \
 	$(QUANTUM_PATH)/encoder/tests/mock_split.c \
 	$(QUANTUM_PATH)/encoder/tests/encoder_tests_split_left_gt_right.cpp \
 	$(QUANTUM_PATH)/encoder.c
@@ -33,6 +36,7 @@ encoder_split_left_lt_right_CONFIG := $(QUANTUM_PATH)/encoder/tests/config_mock_
 
 encoder_split_left_lt_right_SRC := \
 	platforms/test/timer.c \
+	drivers/encoder/encoder_quadrature.c \
 	$(QUANTUM_PATH)/encoder/tests/mock_split.c \
 	$(QUANTUM_PATH)/encoder/tests/encoder_tests_split_left_lt_right.cpp \
 	$(QUANTUM_PATH)/encoder.c
@@ -43,6 +47,7 @@ encoder_split_no_left_CONFIG := $(QUANTUM_PATH)/encoder/tests/config_mock_split_
 
 encoder_split_no_left_SRC := \
 	platforms/test/timer.c \
+	drivers/encoder/encoder_quadrature.c \
 	$(QUANTUM_PATH)/encoder/tests/mock_split.c \
 	$(QUANTUM_PATH)/encoder/tests/encoder_tests_split_no_left.cpp \
 	$(QUANTUM_PATH)/encoder.c
@@ -53,6 +58,7 @@ encoder_split_no_right_CONFIG := $(QUANTUM_PATH)/encoder/tests/config_mock_split
 
 encoder_split_no_right_SRC := \
 	platforms/test/timer.c \
+	drivers/encoder/encoder_quadrature.c \
 	$(QUANTUM_PATH)/encoder/tests/mock_split.c \
 	$(QUANTUM_PATH)/encoder/tests/encoder_tests_split_no_right.cpp \
 	$(QUANTUM_PATH)/encoder.c
@@ -63,6 +69,7 @@ encoder_split_role_CONFIG := $(QUANTUM_PATH)/encoder/tests/config_mock_split_rol
 
 encoder_split_role_SRC := \
 	platforms/test/timer.c \
+	drivers/encoder/encoder_quadrature.c \
 	$(QUANTUM_PATH)/encoder/tests/mock_split.c \
 	$(QUANTUM_PATH)/encoder/tests/encoder_tests_split_role.cpp \
 	$(QUANTUM_PATH)/encoder.c
diff --git a/quantum/keyboard.c b/quantum/keyboard.c
index 1d6657c230..5aaa4b452f 100644
--- a/quantum/keyboard.c
+++ b/quantum/keyboard.c
@@ -689,7 +689,7 @@ void keyboard_task(void) {
 #endif
 
 #ifdef ENCODER_ENABLE
-    if (encoder_read()) {
+    if (encoder_task()) {
         last_encoder_activity_trigger();
         activity_has_occurred = true;
     }
diff --git a/quantum/split_common/transaction_id_define.h b/quantum/split_common/transaction_id_define.h
index 4d4d2b9570..05b3bf7b62 100644
--- a/quantum/split_common/transaction_id_define.h
+++ b/quantum/split_common/transaction_id_define.h
@@ -31,6 +31,7 @@ enum serial_transaction_id {
 #ifdef ENCODER_ENABLE
     GET_ENCODERS_CHECKSUM,
     GET_ENCODERS_DATA,
+    PUT_ENCODER_TAIL,
 #endif // ENCODER_ENABLE
 
 #ifndef DISABLE_SYNC_TIMER
diff --git a/quantum/split_common/transactions.c b/quantum/split_common/transactions.c
index 2b9423cd63..2cfa83e7a3 100644
--- a/quantum/split_common/transactions.c
+++ b/quantum/split_common/transactions.c
@@ -234,21 +234,28 @@ static void master_matrix_handlers_slave(matrix_row_t master_matrix[], matrix_ro
 #ifdef ENCODER_ENABLE
 
 static bool encoder_handlers_master(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]) {
-    static uint32_t last_update = 0;
-    uint8_t         temp_state[NUM_ENCODERS_MAX_PER_SIDE];
+    static uint32_t  last_update = 0;
+    encoder_events_t temp_events;
 
-    bool okay = read_if_checksum_mismatch(GET_ENCODERS_CHECKSUM, GET_ENCODERS_DATA, &last_update, temp_state, split_shmem->encoders.state, sizeof(temp_state));
-    if (okay) encoder_update_raw(temp_state);
+    bool okay = read_if_checksum_mismatch(GET_ENCODERS_CHECKSUM, GET_ENCODERS_DATA, &last_update, &temp_events, &split_shmem->encoders.events, sizeof(temp_events));
+    if (okay) {
+        encoder_handle_slave_events(&split_shmem->encoders.events);
+        transport_write(PUT_ENCODER_TAIL, &split_shmem->encoders.events.tail, sizeof(split_shmem->encoders.events.tail));
+        split_shmem->encoders.checksum = crc8(&split_shmem->encoders.events, sizeof(split_shmem->encoders.events));
+    }
     return okay;
 }
 
 static void encoder_handlers_slave(matrix_row_t master_matrix[], matrix_row_t slave_matrix[]) {
-    uint8_t encoder_state[NUM_ENCODERS_MAX_PER_SIDE];
-    encoder_state_raw(encoder_state);
     // Always prepare the encoder state for read.
-    memcpy(split_shmem->encoders.state, encoder_state, sizeof(encoder_state));
+    encoder_retrieve_events(&split_shmem->encoders.events);
     // Now update the checksum given that the encoders has been written to
-    split_shmem->encoders.checksum = crc8(encoder_state, sizeof(encoder_state));
+    split_shmem->encoders.checksum = crc8(&split_shmem->encoders.events, sizeof(split_shmem->encoders.events));
+}
+
+static void encoder_handlers_slave_reset(uint8_t initiator2target_buffer_size, const void *initiator2target_buffer, uint8_t target2initiator_buffer_size, void *target2initiator_buffer) {
+    uint8_t tail_index = *(uint8_t *)initiator2target_buffer;
+    encoder_set_tail_index(tail_index);
 }
 
 // clang-format off
@@ -256,7 +263,8 @@ static void encoder_handlers_slave(matrix_row_t master_matrix[], matrix_row_t sl
 #    define TRANSACTIONS_ENCODERS_SLAVE() TRANSACTION_HANDLER_SLAVE_AUTOLOCK(encoder)
 #    define TRANSACTIONS_ENCODERS_REGISTRATIONS \
     [GET_ENCODERS_CHECKSUM] = trans_target2initiator_initializer(encoders.checksum), \
-    [GET_ENCODERS_DATA]     = trans_target2initiator_initializer(encoders.state),
+    [GET_ENCODERS_DATA]     = trans_target2initiator_initializer(encoders.events), \
+    [PUT_ENCODER_TAIL]      = trans_initiator2target_initializer_cb(encoders.events.tail, encoder_handlers_slave_reset),
 // clang-format on
 
 #else // ENCODER_ENABLE
diff --git a/quantum/split_common/transport.h b/quantum/split_common/transport.h
index 2e2b918d45..4f6b968fa8 100644
--- a/quantum/split_common/transport.h
+++ b/quantum/split_common/transport.h
@@ -65,8 +65,8 @@ typedef struct _split_master_matrix_sync_t {
 
 #ifdef ENCODER_ENABLE
 typedef struct _split_slave_encoder_sync_t {
-    uint8_t checksum;
-    uint8_t state[NUM_ENCODERS_MAX_PER_SIDE];
+    uint8_t          checksum;
+    encoder_events_t events;
 } split_slave_encoder_sync_t;
 #endif // ENCODER_ENABLE